Karthik (who used to head HR at Texas Instruments India) and has started his journey as an OD consultant a couple of months before I started mine (in fact I wrote about it here) has also started a blog - "OD and more".
His post on development of leaders is particularly brilliant, IMHO.
imagine a depiction of a 3D space with an X-axis, a Y-axis and a Z-axis, and a 0,0 point at the center. To me, the 0,0 point is the "bindu" - the core - and it has to do with "Awareness of Self"(identity, values, angst, quest, yada yada yada). The X-axis has to do with "managing reporting relationships" be they the management of one's team/reports or one's boss / management system (issues here - roles, control, authority, taking a location etc). The Y-axis has to do with "influencing non-reporting relationships" (influence, interface management, peerage, etc). Finally the Z-axis - to do with customer knowledge, business acumen, competitor awareness, product familiarity, technology-savvy, environmental awareness, future-orientation etc.
So the true organizational leader is one who has all these axes developed and if any one of these is faulty or underdeveloped, the leader will not be overall effective. The crux of the matter is the 0,0 point that Karthik talks about. Most of the time it is the least explored aspect and therefore the most difficult to confront and realise too.